Even if you’re not the Michelangelo of pumpkin carving, you can still make a memorable jack-o’-lantern using a bit of grade school science. All you need is water, dish soap, baking soda, food coloring, and vinegar. The same ingredients used in a science fair volcano can make your pumpkin appear to puke or ooze disgusting slime from its orifices.
You can do something like this with fake blood and a water fountain pump, put an elevated pumpkin in a birdbath and a few gallons of fake blood (not sure how thick it can be), place the water pump set at a low flow setting in the birdbath behind the pumpkin with the water tube going into the pumpkin so the fake blood oozes out of the pumpkin non stop. I’m sure if you have the holes small enough you can have the flow rate set so the blood comes out of the mouth and the eyes